Magneto-rheological fluid dampers typically include a damper body with a sliding piston rod received therein. The damper body includes a reservoir that is filled with magneto-rheological fluid, i.e., non-colloidal suspension of micron-sized magnetizable particles. The damping characteristics are controlled by applying a magnetic field to the magneto-rheological fluid. Magneto-rheological fluid dampers used in semi-active suspension systems designed for heavy vehicles or rough road and off-road vehicles typically require high charge pressures, e.g., 1500 psig, to avoid cavitation and air ingestion. It is desirable to avoid air digestion because it causes permanent reduction of damper performance. It is desirable to minimize cavitation because it causes a temporary reduction of damper performance and erosion of the damper materials. However, at such high charge pressures, seals used in containing magneto-rheological fluid within the damper body as the piston rod reciprocates within the damper body are likely to be short-lived.